The purpose of this study is to evaluate the relationship between mother and child as it develops over time. The problem is an old one, to which we bring a unique set of observational data and a new analytic coding scheme. The data are unique in that (a) they are based on a set of behavior samples that are chosen to be representative of the range of functions and demands involved in parenting, and (b) they are obtained at three successive periods of development (early, middle, and late childhood). Mother and child behaviors are coded in terms of verbal communication, use and regulation of affect, regulation and control of behavior, nature of involvement, and sensitivity to other's needs. One purpose of the observational system is to identify organized patterns (a) in the social-emotional development of the child, (b) in mother-child interactions and the development of their relationship, and (c) in the methods, mother and child use to cope with stress.